Got brook trout? Then you’ve also got a healthy stream

“A wild trout in its native habitat is a compact example of the Earth working well.” — Christopher Camuto

The brook trout (Salvelinus fontinalis) is a small, brilliantly colored freshwater fish native to clear, cold streams and rivers in the headwaters of the Bay watershed. It’s also the state fish of New York, Pennsylvania, Virginia and West Virginia.

Brook trout are recognized by their dark green back covered with lighter, worm-shaped markings. These markings, resembling the pattern created when the sun shines through rippled water, help to camouflage brook trout from predators such as larger fish and herons and even fly fishers. Bluish sides are sprinkled with yellow spots and red spots surrounded by blue halos. The brook trout’s fins are starkly edged in white, which again is unique among other common trout.

Brook trout have a dark green back covered with lighter, worm-shaped markings. These markings, resembling the pattern created when the sun shines through rippled water, help to camouflage brook trout from predators such as larger fish and herons and even fly fishers. (USF&WS)

These fish thrive in clear, silt-free, well-shaded freshwater streams with numerous pools and a substrate made of mixed gravel, cobble and sand. Because brook trout are not tolerant of water temperatures above 75 degrees Fahrenheit, they are rarely found in developed areas.

Brook trout are not picky eaters and eat a wide variety of food. Opportunistic feeders, they will eat whatever they can find, including: aquatic insects, like mayflies, caddisflies and stoneflies; land insects that fall into the water, like ants and beetles; small crayfish; and even small fish and minnows, but only when they are easy to catch.

Brook trout spawn in autumn, mainly in October to November. The female uses her tail to create a shallow nest or “redd,” often near the lower end of the pools where the gravel is swept clean of silt and fresh oxygenated water is abundant. There, she deposits eggs, which the male then fertilizes. During spawning, the lower flanks of males become brilliant orange, and older males may develop a slightly hooked lower jaw.

The female covers the fertilized eggs with gravel. The eggs incubate through the winter and hatch in early spring. Brook trout mature in two to three years and live about six years. Most grow no more than 9–10 inches. A 12-inch brook trout is rare and considered a real trophy.

Though small, brook trout have always been a prized game fish, and are an especially popular catch for fly fishermen.

A native brook trout in the Catoctin Mountains of Frederick County

In addition to being noted for their recreational value, brook trout are also very significant biologically. Because they require pristine, stable habitat with high water quality conditions, brook trout are viewed as indicators of the biological integrity of streams. As the water quality in headwater streams has declined so have brook trout populations.

Agriculture impacts to brook trout populations are similar to those of urbanization: increased water temperature, increased sedimentation, changes in hydrology and loss of streamside vegetation. Additionally, livestock can pollute water and damage stream banks, increasing the erosion of sediments that then enter waterways.

Mining activities impact brook trout populations through acid mine drainage, hydrological changes and physical habitat degradation. Nonnative fish, such as brown trout, compete with native brook trout for food and habitat. Brook trout populations can also become isolated because of physical barriers like dams, which decreases genetic diversity and the survival of the species.

Recognizing the uniqueness of the Eastern brook trout and its decline in this region, an alliance, the Eastern Brook Trout Joint Venture, formed in 2004. This partnership of state and federal agencies; regional and local governments; businesses; conservation organizations; academia; scientific societies; and private citizens is working to protect, restore and enhance brook trout populations and their habitats across their native range.

Eastern Brook Trout Joint Venture works on a variety of activities including: identifying and prioritizing brook trout restoration and conservation projects; restoring brook trout habitat using bank stabilization, instream structures and streamside plantings; removing dams and other stream blockages; and promoting livestock fencing. Today, the partnership is made up of more than 370 agencies and organizations, including citizen groups, from Maine to Georgia.

From 2004 through 2015, the Eastern Brook Trout Joint Venture worked to remove 72 dams and barriers — which opened more than 200 miles of rivers — and restored more than 200 miles and nearly 500 acres of rivers and streams for wild brook trout.

These efforts not only help brook trout but provide economic benefits to local communities by providing buffers against flooding, increasing fishing and boating opportunities and increasing property values through the improvement of the local environment.